The windings of electric motors and generators typically have jumper leads that connect the individual coil groups that comprise the windings. These leads must be electrically insulated, especially in high voltage applications, such as between 2300 and 6900 volts, where arcing can occur.
To provide such electrical insulation, it is known to hand wind several layers of an insulating tape around the jumpers. This insulating tape can be constructed of a paper material containing mica.
The hand-winding of mica tape results in multiple layers of insulative material having sufficient dielectric and corona resistance properties, while retaining adequate flexibility. Further, it is known to impregnate the hand-wrapped mica tape with an epoxy resin.
The process of winding mica tape and other insulating materials around the jumper leads of electrical winding is labor intensive. Further, hand taping may lead to repetitive work injuries.
The coil leads of lower voltage motors are sometimes covered with sleeves of a single layer insulative material. However, a single layer of mica paper or similar insulation does not provide sufficient insulation for higher voltage applications without making the layer too thick to provide adequate flexibility.
It is also known to cover the leads of high voltage coils with sleeves constructed of fiberglass coated with silicone or acrylic, allowing for increased flexibility. However, since the voltage endurance of such materials is generally inferior to that of mica tape, these fiberglass sleeves must be used throughout the entire coil, rather than just around the leads extending therefrom.